Case 1:

Smart Developer is a software development company based in Bombay. It has a branch office in Delhi. James William is a network administrator in the head office (Bombay). The management of the organization asked James to synchronize data between head office and branch office.

The head office maintains database in Oracle and the branch office in SQL Server.

The management also wants that James should follow the following conditions while synchronizing data:

• James should perform the synchronization over Internet.
• James should control the replication process at head office.
• The synchronization process should occur twice in a week.
• The synchronization process should start on 01, Jan, 2007 at 7:00AM and should end on 25, May, 2009 at 10:00PM.

Solution:

To solve this problem, James needs to follow the following steps:

1. InstallReplicator at head office to control the replication process.
2. InstallReplication DataSource at branch office to synchronize data over Internet.
3. ConfigureJDBC DataSource in Replicator to reterieve data from Oracle database.
   
4. ConfigureJDBC DataSource in Replication DataSource to reterieve data from SQL Server database.
   
5. ConfigureSettings required for Replicator and Replication DataSource.
6. AddReplication DataSource in Replicator so that they can interact with each other.
7. CreateSubscription using Publisher-Subscriber Model. In this case, James can consider the Branch Office as Publisher and Head Office as Subscriber. James should select the Bidirectional while creating the subscription because he wants to synchronize data between head office and branch office.
8. AddSchedules in Replicator. In scheduling, James needs to perform Non Real Time Scheduling. And he should set the Recurrence Type as Weekly and Counter Value as 2, because the management asked him to execute the synchronization process twice in a week. He should also set the start date as 01-01-2007, start time as 07:00AM, end date as 25-05-2009, and end time as 10:00PM.

Following figure shows synchronization of data between head office and branch office using Publisher-Subscriber Model:

Data Synchronization using Publisher_Subscriber Model

This figure shows that Replication DataSource retrieves changes from the SQL Server database and merges it into the Oracle database with the help of Replicator. In addition, Replicator sends changes made in Oracle database to Replication DataSource and Replication DataSource merges it into the SQL Server database.


Case 2:

ABC Systems is an IT solution firm in Sydney, Australia. There are three marketing personnel A, B, and C. They have their own Lap Top. They record their clients data in their own database on the Lap Top.

• A is maintaining database in SQL Server.
• B is maintaining database in PostGreSQL.
• C is maintaining data in DB2.

The manager of the organization asked all of them to merge the local data stored on their Lap Top to the main database. The main database of the organization is in Oracle. In addition, the management asked all of them to perform replication over Internet and control the replication process on their own Lap Top.

Solution:

To solve this problem, A, B, and C needs to perform the following steps:

1. InstallReplicator on their Lap Top to control the replication process.
   
2. InstallReplication DataSource on the main system (having main database) to perform the replication process over Internet.
3. ConfigureJDBC DataSource in Replicator to reterieve data from the SQL Server, PostGreSQL, and DB2 databases respectively.
4. ConfigureJDBC DataSource in Replication DataSource to reterieve data  from main database.
5. ConfigureSettings required for Replicator and Replication DataSource.
6. AddReplication DataSource in Replicator so that they can interact with each other.
7. CreateSubscription using Publisher-Subscriber Model. In this case, A, B, and C can consider their Lap Top as Publishers and the main database as Subscriber.
   
8. ExecuteSubscription to merge local data into main database.

Following figure shows how to merge local data into main database using Publisher-Subscriber Model: